When your furnace starts to make strange noises, you will want to look into the cause of that noise. There are a number of reasons why your furnace could be making noises, which is why it is important to understand the different reasons your furnace could be making those noises.
Sound #1: Rattling Noise
The first sound you need to watch out for is rattling. A rattling sound coming from your furnace often has a straightforward cause. For example, a rattling sound often comes from a simple loose panel that needs to be tightened up or from a loose screw. You can check your furnace and see if anything is loose and tighten it up to see if that fixes the noise.
If a panel or screw is not loose, the rattling noise could be something more serious. Instead, you could have a crack or a leak in your heat exchanger. If your heat exchange is damaged, it could leak carbon monoxide into your home, which is why this is a pressing issue to address.
Sound #2: Popping or Pinging
The second sound you should be aware of is a popping or pinging sound. A popping or pinging sound happens when there is a thermal expansion in your system. Basically, your ductwork is expanding and contracting as it heats up and cools down. But, again, this is natural and normal.
You should inspect your ductwork and ensure that it is secure and in place. You may also want to insulate your ductwork so that it doesn't experience so much thermal expansion.
Sound #3: High Pitch Squeal
The third sound you need to be aware of is a high pitch squeal. This sound can be really irritating to your ears and is something you will want to address right away.
A high-pitch squeal is often associated with some major issues, such as a damaged blower belt or a shaft bearing that is not properly lubricated and thus is getting damaged. Or the blower motor could just be damaged. A high pitch has to be addressed right away and shouldn't be ignored.
Sound #4: Scratching Sound
The fourth sound you need to be aware of is a scratching sound, where two pieces of metal are grinding against each other. This is another severe sound. If you hear metal scraping on metal, you should turn off the furnace right away.
This sound usually means that your blower fan is broken or loose. Also, it could be hitting the housing inside your furnace and causing more damage.
When you have a furnace, you need to pay attention to the sounds that it makes. If your furnace is making an alarming sound you are not familiar with, you will want to get a heating repair professional out to investigate and fix your furnace right away.